An AI language tutor that works without internet
Most apps that call themselves “offline” give you flashcards and word lists. The moment you want to practise a conversation you need a connection again, because the AI doing the talking lives on a server. Sayelle is different. The tutor model, speech recognition and text-to-speech all run on your phone. Once they're downloaded, a spoken conversation works the same on a flight in airplane mode, in a subway tunnel, or anywhere else with no signal.
What runs on your device
Three models download once, over Wi-Fi, about 4 GB in total. Qwen3.5 4B, a 4-bit open-weight language model, writes the tutor's replies. Whisper turns what you say into text. Kokoro reads the answers out loud. None of them needs a server to work, so the conversation you have, speaking, being listened to and answered, happens on the phone in your hand.
What you need to run it
Because the AI runs on your phone, Sayelle works best on a recent phone with plenty of memory. On iPhone you need iOS 18 or later. On Android you need Android 8.0 or later, and 8 GB of memory or more is recommended. Allow about 4 GB of free space for the one-time download. On older or lower-memory phones, conversations may be slower and the app may close during voice practice. On Android, Sayelle shows a one-time notice if your phone is below the recommended memory.
What still needs a connection
Signing in, purchases, ads, Cloud Sync and downloading new lessons or scenarios all need internet. If you're signed in with Cloud Sync on, your text transcripts and progress sync to Sayelle's backend next time you're connected. The conversation itself, speaking, listening and replying, never waits on that. The FAQ and Privacy Policy have the complete picture.
Why running the AI locally matters
Working on a plane is the obvious benefit. The less obvious one is privacy: your voice isn't streamed to a server to get a reply. Raw microphone audio is processed on your phone and isn't uploaded. It also means the app's main feature doesn't depend on a third-party AI provider's uptime or rate limits. The model talking to you is the one on your phone.
How it compares to other “offline” language apps
Plenty of well-known apps have offline modes, and they're useful for reviewing vocabulary, replaying downloaded audio, or working through flashcards without a signal. What most of them still need the internet for is the part that feels like a conversation: an AI that listens to open-ended speech and answers naturally, instead of picking from a fixed script. That's the part that runs on your phone in Sayelle. For a side-by-side with one popular app, see Sayelle vs Duolingo.
Common questions
Does Sayelle really work in airplane mode?
Yes, once you've downloaded the models and the lessons or scenarios you want. The tutor, speech recognition and voice all run on your phone, so a spoken conversation works with no signal.
Which AI models does Sayelle run on the device?
Qwen3.5 4B, a 4-bit open-weight language model, writes the tutor's replies. Whisper turns your speech into text. Kokoro reads the answers aloud.
How big is the download?
About 4 GB in total, downloaded once, ideally over Wi-Fi. Lessons and scenarios you choose to keep offline are extra.
What phone do I need?
iOS 18 or later on iPhone, or Android 8.0 or later with 8 GB of memory or more recommended. It works best on a recent phone with plenty of memory.
What still needs the internet?
Signing in, purchases, ads, Cloud Sync and downloading new lessons or scenarios. The conversation itself doesn't.
Is my voice uploaded?
No. Raw microphone audio is processed on your phone and isn't uploaded. If you're signed in with Cloud Sync on, text transcripts and progress sync when you're connected.
Try it
Sayelle is free to start, with nine languages supported today: English, Spanish, French, Italian, Portuguese, German, Chinese, Hindi and Japanese. Or read more on the homepage.
